Earth was assumed to be the only planet in the solar system with liquid water. But space scientists now understand that this is not the case, following the decades of missions by the US space agency NASA.

NASA has now launched its Ocean Worlds Exploration Program, in an audacious attempt to track aquatic alien life.

There could be some NASA's Dr Amanda Hendrix

Dr. Amanda Hendrix, co-lead by NASA's Roadmaps to the Oceans World Group, explains how the Ocean World Program represents one of the best

"We need to understand whether these oceans are habitable and if so whether these oceans actually a host life. "

She said: "The Huygens Probe that was part of the Cassini-Huygens mission, landed on Titan's surface."

"The probe was not designed to investigate the habitability of

"But there is a mission concept, which is currently under investigation at NASA, the Dragonfly mission, which would both land on Titan's surface and fly around in Its atmosphere, using a quadcopter-type design.

"This would tell us a lot about the habitability of Titan's surface."

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